So you've cloned a repo and made some changes? Now you want to submit a PR. This'll make it look like you didn't forget to fork before making the changes. Zero loss of face and endless enjoyment.

1. Fork the repo on GitHub.

2. Rename the local remote.

   git remote rename origin upstream

3. Add your fork as the new origin.

   git remote add origin git@github:...my-fork.git

4. Fetch the fork to update your branches.

   git fetch origin

5. Create a new branch with your changes.

   git branch changes

6. Checkout your fork's master branch. (This resets the current master branch so changes will be lost.)

   git checkout -B master --track origin/master

7. Rebase your changes onto the new master.

   git rebase changes

8. Optionally remove your temporary changes branch.

   git branch -d changes

9. Push your changes to your fork so you can create a PR on GitHub.

   git push

Credit goes to @jagregory for the original this is based on.